Improvement in combined square and bevel



J. D. HOBBS. Combined Square and Bevel.

No. 222,354. Patented Dec. 9-, 1879'.

I'll lldl'llllgllll'l .ble along the slot.

UNITED STATES PATENT OFFICE;

JOSEPH D. HOBBS, OF MEDIAPOLIS, IOWA.

IMPROVEMENT IN COMBIN ED SQUARE AND BEVEL.'

Specification forming part of Letters Patent N0.222,354, dated December9, 1379 application filed October 9,1879.

To all whom it may concern:

" Patterns, of which the following is a specification.

The object of my invention is to provide a .method whereby a given slantor angle may be transferred from the given object to any object ofmeasurement in mechanical constructions alone.

The invention consists of a tri-square-shaped tool, with arms E and K ofcorresponding length, with a tongue or drop-extension, L, to

perfect square, said tongue or drop-extension L being the third arm ofthe tri-square. The arm E is scalloped at the end. The arm K istraversed nearly its entire length by a narrow slot, in which works athumb-screw bolt, mova- This thumb-screw bolt clasps a simple movablebar or yoke, H, about two-thirds of its length from the end, making saidbar or yoke H correspond with the arm E. This movable bar or yoke Hmaybe made to register any slant or angle on the graduated arm K byadjusting it by means of the thumb-screw bolt. The object of this deviceis to transfer given angles or slants in mechanical structures to anydesired object of measurement after having obtained the given angles orslants by means of a square or bevel.

Theoperation in a particular case, as applied to hub-mortises, is asfollows: Take the improved bevels, as shown and described in my previouspatent, No. 213,987, of April 8, 1879, insert the two arms in themortise, fasten them at the right slant, then apply the arms of thebevel with the slant thus obtained to the arm E and the bar or yoke H ofthe pattern; adjust the bar or yoke H, by means of thethuinbscrew bolt,so as to make the arm E and the bar or yoke H correspond with the armsof the bevels'. Thus the slant of the mortise is transferred to thepattern and registered by the bar or yoke 11 on the graduated arm K.Then put the pattern on the spoke, and make the spoke correspond exactlywith it. In this way the spoke is made to fit without danger.

of mistake, system. I i

Again, to obtain the slant by use of the pattern alone, place the bar oryoke H atthe base of the object of measurement, then loosen thethumb-screw bolt, move the tongue or dropextension L till it correspondsin slant with the slant of the object of measurement,tighten thethumb-screw, and the proper slant may then be obtained and transferredto the desired object.

\(Vhat I claim is The tri -square, with graduated arm traversed nearlyits entire length by a narrow slot, in which works a thumb-screw bolt,which bolt clasps a movable bar or yoke, capable of registering on thegraduated arm by proper adj ustment with the corresponding arm any slantor angle, by means of the graduated arm and the thumb-screw bolt, andthe tongue ordrop-extension to the graduated arm, making, with thecorresponding arm above, a perfectsquare, as above described.

and does away with the old block JOSEPH n. HOBBS.

